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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Coagulation

Protein C (Activity)

Protein C Activity testing evaluates a critical component of your natural anticoagulant system. Proactive screening identifies deficiency before a thrombotic event occurs.

What It Measures

This test measures the functional anticoagulant activity of Protein C, expressed as a percentage of normal.

Why It Matters

Protein C deficiency, whether inherited or acquired, is an important cause of thrombophilia. Early identification allows preventive measures during high-risk situations.

When to Test

Testing can be indicated for unexplained venous thrombosis, family history of Protein C deficiency, or as part of thrombophilia screening. Avoid testing on warfarin as it suppresses Protein C.

Symptoms

Low Levels

Low Protein C activity increases thrombosis risk. In adults, symptoms relate to thrombotic events (DVT, PE) rather than the deficiency itself.

High Levels

Elevated Protein C activity is generally not clinically significant and does not require intervention.

Lifestyle Tips

If Protein C deficiency is confirmed, reduce thrombosis risk factors, discuss anticoagulation for high-risk situations, and inform family members who may benefit from testing.

Frequently Asked Questions

How common is Protein C deficiency?
Inherited Protein C deficiency affects about 1 in 200-500 people. Most are heterozygous with moderately reduced levels.
Why avoid testing on warfarin?
Warfarin suppresses vitamin K-dependent proteins including Protein C, giving falsely low results.
Is Protein C related to Protein S?
Yes. Protein S is a cofactor for Protein C. Both are vitamin K-dependent natural anticoagulants.